The invention relates to a system for opening and closing a folding top or moveable vehicle roof of a convertible car.
A system of this class is disclosed in the U.S. Pat. No. 5,225,747. In this system an arrangement of sensors is chosen for a convertible top. With this system the opening and/or closing motion of the convertible top can be sensed over at least one defined range of movement. The system comprises drive means, which are connected to parts, for example, linkage elements, for opening and closing the convertible top. In addition, there are position sensors in the form of pivot point sensor that are arranged in the hinge area of the linkage. These pivot point sensor sense the movement of the convertible top at least over one range of movement and send a corresponding signal to a controller, which defines and controls the further actuation of the convertible top based on the input signals.
Proceeding from this state of the art, the object of the present invention is to improve such a system that the position sensors can be arranged at positions near the drive.
This problem is solved by the arrangement of at least one position sensor is designed as a linear sensor in such a manner that the position of two moveable elements of the folding top or moveable vehicle roof relative to each other can be sensed; or the position of one moveable element of the folding top or moveable vehicle roof relative to a fixed reference point of the vehicle can be sensed. This design of the position sensor makes it possible to arrange it not only in the area of a hinge of one element of the folding top or moveable vehicle roof, but especially in the vicinity of a drive.
According to a special embodiment, the position sensor can be coupled with drive means, and in particular can be integrated into it. This embodiment has turned out to be especially advantageous when the drive means also perform a linear movement when opening or closing the folding top or moveable vehicle roof, for example, when the drive means comprise a piston-cylinder arrangement (e.g. hydraulic cylinder), which moves back and forth when actuating the folding top or moveable vehicle roof.
The elements of the folding top or moveable vehicle roof that are to be sensed in a special manner are its main pillar and hold down clamp. For this reason in a preferred embodiment of the invention the sensor is arranged in such a manner that the position of the main pillar or a hold down clamp of the folding top or moveable vehicle roof to a fixed reference point of the vehicle or to another reference point of the folding top or moveable vehicle roof can be found.
Of course, in addition to a linear sensor, still other sensors, like the pivot point sensors or end position switches that are described in the U.S. Pat. No. 5,225,747, can be used. However, what is relevant for the present invention is that at least one linear sensor is used.
The linear sensor can be designed as a magnetoresistive sensor, and in particular comprise a magnetized ferrite rod, where the ferrite rod can be magnetized spirally and, as the ferrite rod moves, it is guided past a magnetic field sensor. In addition, the linear sensor can work according to the principle of variable inductivity, where, for example, a ring can be arranged on a rod so that, as the rod moves, the ring is guided past a coil. In this manner the position of the rod can also be found in a simple and inexpensive manner. As an alternative, a conductive piston inside a coil could trigger such feedback on the coil that the position of the piston can be inferred from the changing signal voltage.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.